Fraunhofer

Definition

Fraunhofer lines are dark absorption lines in the solar spectrum, named after the German physicist Joseph von Fraunhofer. They result from specific wavelengths of light being absorbed by elements in the Sun's atmosphere.

5 Must Know Facts For Your Next Test

1. Fraunhofer lines were first observed by William Hyde Wollaston but extensively studied and cataloged by Joseph von Fraunhofer.
2. They provide evidence for the presence of various elements in the Sun's atmosphere, such as hydrogen, helium, and calcium.
3. These lines are crucial for understanding stellar composition through spectroscopy.
4. Fraunhofer identified around 570 dark lines and labeled the most prominent ones with letters A through K.
5. The study of these lines has been fundamental in developing our knowledge of atomic transitions and quantum mechanics.

Review Questions

• Who is credited with cataloging Fraunhofer lines?
• What do Fraunhofer lines indicate about a star’s atmosphere?
• How many prominent dark lines did Fraunhofer label in his studies?

Related terms

Spectroscopy: A technique used to analyze light spectra to determine properties of astronomical objects.

Absorption Spectrum: A spectrum that shows dark lines or bands where light has been absorbed by atoms or molecules.

Emission Lines: Bright lines in a spectrum caused by emission of photons from atoms transitioning to lower energy states.